The present invention relates generally to the field of water separation, and more particularly, but not by way of limitation, to a water separation system having a submersible pump.
Handling water in high water cut fields presents a big problem for oil and gas producers. Fluid separation and reinjection systems are an important and expensive part of most hydrocarbon production facilities. The separation of fluids and solids based on different properties is known in the industry. A variety of separation methods are used, including gravity separators, membrane separators and cyclone separators. Each of these separator types uses a different technique to separate the fluids and each a different efficiency depending upon the device and its application.
Gravity separators, for instance, can be efficient when there is a great density difference between the two fluids and there are no space or time limitations. Another type of separator, the membrane separator, uses the relative diffusibility of fluids for separation. Any separation method that is time dependant, such as the above mentioned gravity and membrane separators, does not work well with an electric submersible pump underground but can be adapted if the separator is located above ground. Electric submersible pumps (ESP) are capable of producing fluids in a wide volume and pressure range and are often used for downhole fluid production. These pumps are used very efficiently for applications where downhole oil water separation devices are used.
Hydro cyclone separators are non-rotating devices, using a specific geometric shape to induce fluid rotation. This rotation creates high g-forces in the fluids as the fluids spin through the device. This process results in the lighter fluids forming a core in the middle of the separator. In the handling of oil and water mixtures, the inner core is extracted out of the topside of the hydro cyclone separator as a production oil stream. The separated water is rejected from the bottom side. One problem associated with this type of separator is the large pressure drop experienced as the fluid passes through the hydro cyclone.
There is a need in the industry for a less expensive, simple clean water injection system that can be placed at any location in the wellbore, is adaptable to changing conditions and can handle large volumes of water and other debris such as sand.
The present invention, overcomes these problems by providing a system using a separation and pumping device on the surface in conjunction with an submersible pumping device.
The present invention provides a clean water injection system featuring a downhole electric submersible pumping device coupled with a surface separator and a high pressure surface pumping system for the separation and transfer of separated fluids to different locations or zones. Since the separator and pumping system are on the surface, the separation system arrangement is not restricted to downhole conditions.
The objects, advantages and features of the present invention will become clear from the following detailed description and drawings when read in conjunction with the claims.